We just completed our (Nov 10-17 2001) Mexico trip on the Sea Princess and though we chose traditional seating we decided to give some extra cash to our two servers directly even though $6.50 comes off our account daily per person.
We also gave cash to our room steward and in our case because he really made a difference, gave him some more also.
I liked the automatic dining room off my accout for the current $6.50 and do not have a problem with them increasing to $10 to cover the cabin steward.
You do have complete flexability to adjust your account up or down and pursers office will do wht you ask. With 2,000 + folks , you can belive they will not remember you, unless you make a fuss.
What most folks do not know is that your cabin steward can have someone working for them and your tip becomes shared.
Also the amounts are set by an industry guideline by American Express from what I last heared.
I have given our tip the 2nd to last day or early on the last sea day and this time left some extra small bills in CDN & Peso dollars for when they are at thse ports. Called it coffee money.
When we gave our waiter and his helper some extra tips and said we knew it was extra they were quite pleased and we belive even that money will get shared with the folks directly doing your table, in our case.
Our waiter told us the two of them look after 30 people.
ps: its a good idea as it saves you bringing cash on board and worring if you have enough/ For the staff, given we all do not reduce it to zero , they tend to get more
On another note, on the last day, Princess sets up a table with envelopes that you can oick up with blank or pre-printed position names.